(a) Technical Field of the Invention
The present invention relates to cap structure, and in particular, to a cap structure for inspection of water pressure leakage within the radiator of a vehicle.
(b) Brief Description of the Prior Art
Taiwanese Utility Model application no. 90217830 entitled “Water Pressure Leakage Inspection Cap Structure” (shown in FIG. 1) discloses a cap structure having a mounting block to increase the contact surface of the screw shaft and a sealing cap, the leakage proof member at the bottom of the screw shaft is effectively mounted to seal the mouth of the radiator to allow accuracy of inspecting water pressure thereof. The drawback of this conventional cap is that while turning the cap, the upper end of the sealing cover is too long, and therefore the exertion of a force is difficult. Further, the surface of the cap is too thin, this makes gripping thereof a problem. The addition of a mounting block causes fabrication process laborious. Accordingly, it is an object of the present invention to provide a cap structure for a radiator used in vehicle which mitigates the drawbacks mentioned above.